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As will be seen by the illustration, this Barometer is built on original lines.
By the absence of the ordinary tubular enclosures (in the usual form of instrument) the mercurial column is FULLY EXPOSED to view, NO SHADOWS are thrown upon the column, and therefore an extremely accurate and instantaneous reading is made possible. The scales being graduated upon the flat side pieces the DIVISIONS AND FIGURES ARE ALWAYS IN VIEW, and the vernier is very much more legible than in the ordinary tubular patterns.
The bore of the tube is 0.5 inch.
The scales are graduated in inches and millimetres, and, by means of the verniers, are capable of being sub-divided to read to 0.002 inches and 0°1 m/m.
The attached Thermometer on the body of the instrument is graduated in Fahrenheit and Centigrade scales. It is the BOLDEST Standard Barometer made. The PRICE IS LOWER than that of any other form of Standard Barometer of the same dimensions.
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HEAD: 186 STRAND, LONDON, W.C.
THURSDAY, JULY 20, 1905.
ARCTIC METEOROLOGICAL OBSERVATIONS.
The Norwegian North Polar Expedition, 1893-1896; Scientific Results. Edited by Fridtjof Nansen. Vol. vi. Published by the Fridtjof Nansen Fund for the Advancement of Science. Pp. xiv +659; 20 plates. (London: Longmans, Green and Co., 1905.) Price 36s. net.
IT is a misfortune that meteorological results de
mand so many figures for their discussion, and so much space for their exhibition. Vol. vi. of the Norwegian North Polar Expedition, dealing with the climatology of the area through which the Fram drifted in its memorable voyage, 1893-6, is a most interesting book, but its size and appearance might repel any but the most ardent meteorologist. discussion of the observations has been undertaken by Prof. Mohn, of Christiania, and the arrangement is a model of clearness and efficiency. Prof. Mohn superintended the whole meteorological equipment, suggested the plan of work to be carried out during the voyage, and arranged with Captain Scott-Hansen the general management of the meteorological work. We imagine Prof. Mohn must be gratified with the success of his arrangements, and the intelligent interest which the officers of the expedition have shown in the work. Notwithstanding the severity of the climate, there is hardly a gap in the series of observations. At sea, the observations were taken at intervals of four hours, but for the greater part of the time the readings were made every two hours, with a regularity that compels admiration. The result is that we have, with very considerable accuracy, the climatological elements of a region in the circumpolar Arctic Ocean, where the surface of the earth during the whole time was of a unique homogeneous nature, consisting of a level of frozen water, remote from continents and islands, and with an uninterrupted free horizon.
The wind, particularly with regard to direction and velocity, is the first element discussed. To obtain a sufficiently long series of observations for investigation, Prof. Mohn divides the interval into three groups, a dark season when the sun was below the horizon, a sunny season during which the sun was above the horizon for practically twenty-four hours, and the equinoctial months, during which there was regular day and night. The discussion shows that during the dark season the wind shifts generally against the sun. Only during four hours in the twenty-four does the wind veer with the sun, while in the sunny period the wind veers with the sun, backing about six hours, divided into periods of two hours each at three different periods of the day. In the equinoctial months the backing and veering are equal, the wind shifting with the sun during the night and morning, and against the sun from 10 a.m. to 10 p.m. The diurnal period of the wind's direction is a phenomenon which still awaits an explanation, and the different direction of the shift of the wind in
the dark and in the sunny season seems to be of some importance for the solution of the problem. With reference to the velocity of the wind, it is shown to be greater when the sky is overcast than when it is clear. In the former case, the average velocity is 5.09 metres per second (11.4 miles per hour), and in clear weather only 3.54 metres per second (8 miles per hour). The greatest velocity recorded appears to be 40 miles an hour in February, 1896.
The discussions of the variations of temperature are very interesting, but the results drawn from them regarding the periods of the meteorological elements must of necessity be less trustworthy than if there had been a longer series of observations at disposal. It may therefore be premature to draw conclusions as to the connection between the different observed phenomena, and between those phenomena and their probable causes. The desirability of a longer period, and the character of the errors that can be introduced by the comparison of but few values, are shown very readily if we attempt to derive the month of lowest temperature from the figures given. The readings are centigrade, and show the mean temperature for each month :
- 22 78
Mean - 35'59 The great variation of temperature in March, 1896, making it nearly equal to that of April, demonstrates the uncertainty that must accompany any attempt to derive mean values from short periods. But the deductions drawn directly from the observations, and supported as they are in many instances by similar observations made in Arctic latitudes, are not liable be placed the following:-Throughout the dark winter to the same uncertainty. Among these results may months, when the sky is clear, the lowest temperature occurs in the day, the highest during the night. Generally, in the other months, we have the ordinary diurnal period. With the sky overcast, the diurnal period, with a minimum in the early morning hours and maximum after noon, is very well developed in all the months except January.
"The most striking feature," says Prof. Mohn, seems to me to be the distinct diurnal period of the ordinary march in the winter and dark season, with the sky overcast and relatively higher temperatures. The inverted period with clear sky in the dark season seems to be due to the diurnal period of the wind's direction. The dark-season period with its stronger, south-easterly winds, is hardly to be accounted for by the radiation from the sun or sky."
The forms of cloud, the relative humidity, and the amount and character of precipitation are discussed at full length, but do not present results of unusual importance. With regard to the latter, however, it is not altogether uninteresting to notice that the number of days in a year on which rain is probable is 49, while snow may be expected on 157 days, and some form of moisture will be collected on 180 days.
Hail fell on only 5 days throughout the whole period. Rain can fall only from May to October, and July has the greatest number of rainy days, also it is the month which gives rise to the greatest amount of fog. Very considerable care was taken to determine the temperature of the Polar ice, but, naturally, much difficulty was experienced in recovering the thermometers from the bore-holes, in which they might be frozen fast, while during the summer, the viscous ice would close round them, requiring the thermometers to be dug out. Neither is it easy to remove the sources of error from the observations, especially from the effects of brine contained in the ice, which was apt to fill the bottom of the holes even during the coldest season, whilst during the summer all the holes were filled with briny or saline water, the salinity of which decreased inversely as the temperature. This brine percolated from a different level to that in which the thermometer was placed. In the winter time the temperature of the ice increased from the surface downward, and therefore the brine at the bottom of
the hole was probably of too low a temperature. On
the other hand, in the summer time, the ice near the surface was warmer than that lower down, and the brine would be less saline, and consequently lighter in the upper layers than in the deeper, so that in the summer time the temperature reading would again be too low. The result drawn from the observations is that the surface of the ice, in all months with the single exception of June, is warmer than the air. The difference is greatest in December, amounting to 16° F. The surface of the ice, being covered, except during a short time in summer, with snow, is protected from cooling by radiation upwards, and receives heat from the underlying warmer layers. This, no doubt, is the main factor in the explanation, though other causes are suggested by Prof. Mohn.
The book contains also an account of the meteor
T the present day most works on ornithology of a general character are of little permanent value because the broad outlines of the northern fauna have already been adequately dealt with. What we want, and what we so seldom see, are complete life-histories of separate groups of birds, adequately illustrated and described by ornithologists who are both well acquainted with them in the field and are capable of summarising their labours in an accurate scientific account. To do this a very large series of birds must be collected, examined and digested, and this years of travelling and study with little monetary reward as the result. Nevertheless, the although their costly nature must ever be a constant works of such men are of great and permanent value, drawback to the producer. No good form of colour printing is cheap, and as this is a sine qua non iŋ works of this kind, the results can only pass into the hands of a public "fit but few."
The latest of these monographs is that of "The Geese of Europe and Asia," by Mr. S. Alpheraky, and the Russian naturalist is to be congratulated in giving us the first detailed account of this interesting and, we may say literally, confusing group of birds. It is an admirable treatise, full of research in field and museum, and the work of one who has carefully studied the subject from all points of view. There are twenty-four coloured plates by Mr. F. W. Frohawk, which are unfortunately only moderately successful. Twenty-one of these represent the
different kinds of geese described by the author, and for the most part the lithography is weak and hard, and evidently does not do justice to the artist's careful
ological observations made during the sledge expedi- work; whilst the three plates representing the bills tion to Franz Josef Land in 1895-6. From this account we can quote only one remark, which illustrates the determination of the leader of the expedi
tion to secure an unbroken series of observations.
"We had no lantern for the reading of the thermometer, and I tried in vain to construct one, which
would not burn more oil than we could afford to use. But our eyes of course became gradually trained to see in the dark, and even in mid-winter, with no moonlight, there was so much light reflected from the snow that the column of the darkly coloured Metaxylol was dimly visible, and also the figures of the thermometer scale, but not the division marks."
Dr. Nansen therefore apologises for the absence of the decimal reading, which is missing about the
time of new moon. The interest of the book is necessarily largely centred in the fact that the crew of the Fram laboured so diligently and so well to overcome the difficulties that were imposed upon them by the situation in which they were placed. To go up to the crow's nest to take additional readings of the instruments in dark, wintry weather seems to have been a source of positive enjoyment to those who took part in these observations.
of four various kinds are excellent, and will be of the greatest use both to sportsmen and naturalists in the determination of species. The frontispiece to the work represents the assemblage of white-fronted and red-breasted geese on a sandspit, and is from the brush of Dr. Sushkin. The idea of movement exhibiting the various attitudes into which these birds throw themselves is very fairly represented, but the technical work of painting and the drawing of some of the wings, as well as the general composition, leave much to be desired. It seems a thousand pities that chromolithography is a dying art, and that no firm in Europe is capable of turning out first-class work except W. Greve, of Berlin. For all we know, these drawings by Dr. Sushkin and Mr. Frohawk may have been soft and truthful representations of nature, but here we only see hard and black lines such as nature never shows.
Mr. Alpheraky is evidently a keen sportsman as well as a good naturalist, and he rightly holds a high view of the remarkable intelligence of this class
66 Geese, " he says, "afford one of the most difficult kinds of fowling. However cunning man may be, he
finds it extremely difficult to over-reach these wary birds, and in some places one may see them in hundreds of thousands for several weeks at a stretch
without the possibility of securing a single specimen, This is especially the case in thickly populated regions, where the geese already know that danger may threaten them."
By this we know that the writer has toiled and suffered many disappointments. In certain British waters where for three seasons Brent geese were abundant we never obtained more than one good shot with the punt gun in a season. This was generally at the commencement, when the birds arrived in late October. After this date we could only "look" and "long." Other species are equally cunning.
Le Four Électrique: son Origine, ses Transformations et ses Applications. By Adolphe Minet. Ier Fascicule. Pp. 76. (Paris Librairie Scientifique, A. Hermann, 1905.) Price 5 francs.
The key to genera, species, and subspecies with THE application of electric heating to various
which the author furnishes us is an excellent com-
In this excellent monograph the author gives us all we wish to know about the difference of sexes, gradual growth from nestling upwards, plumage variation, moulting, local names, chase, and colour of the soft parts, the latter, perhaps, the most important point of all in the determination of species. Many excellent outline figures of the bills are also given, so that the reader has no difficulty in recognising the differences of the various races even if he feels inclined, as he must sometimes do, to question the necessity of specific separation.
metallurgical and other industries has of late been making very rapid progress. The time seems, therefore, to be well chosen for examining the various stages of development which the electric furnace has passed through.
M. Minet has taken great pains to collect together as much as possible of the available information, and has certainly succeeded in producing an interesting study. Chronologically, he divides his subject into three periods:-(1) laboratory furnaces (1808-1886); (2) industrial furnaces (1886-1890); (3) development of the industrial applications of the electric furnace from 1890 to the present day. The furnaces themselves are classified in nine groups, according to the function of the current and the method of its application. Any historical treatment of such a subject as this, which expects to be generally recognised as authoritative, demands very great care and judgment in its preparation. The present review certainly promises to be the most complete which the electric furnace has yet received.
It is, however, not so clear that the author has succeeded in accentuating just those developments which have been of the greatest influence to the general progress. There are no doubt difficulties in deciding between two such different claims as those of a brilliant invention and of a painstaking scientific investigation. The successful historian must, however, accurately estimate the value of each and decide on the relative merit according to the influence exerted by each upon subsequent development.
The classification of electric furnace processes is complicated, not only by the large number of separate cases which have to be considered, but more especially by the very different purposes for which the electric current is applied. In the first place it is necessary to distinguish between the purely electrothermal and the electrolytic functions of the current. The latter case embraces all such electrolytic methods as are carried out at a moderately high temperature. Here the electric current serves the double function of maintaining the necessary temperature and separating by electrolytic decomposition one or more of the constituents of the materials treated in the furnace.
During recent years the most extensive developments in electric furnace work have centred around the production and application of extremely high temperatures. The direct results of the scientific and